sema_release
sema_release(&pagedep_in_progress, NULL);
sema_release(&newblk_in_progress, NULL);
static void sema_release(struct sema *, struct lock *);
sema_release(&pagedep_in_progress, &lk);
sema_release(&pagedep_in_progress, &lk);
sema_release(&inodedep_in_progress, &lk);
sema_release(&inodedep_in_progress, &lk);